The role of molecular structure on the microscopic thermodynamics: unveiling with Femtosecond Optical Tweezers

TL;DR

This study uses femtosecond optical tweezers to investigate how molecular structure influences microscopic thermodynamics in liquid mixtures, revealing the impact of hydrocarbon chain length and branching on thermodynamic properties.

Contribution

It introduces a noninvasive method to analyze excess thermodynamics in liquid mixtures using FOT, linking molecular structure to thermodynamic and rheological behavior.

Findings

Hydrocarbon chain length and branching affect microscopic thermodynamics.

Excess viscosity and Gibbs free energy vary with molecular structure.

Femtosecond optical tweezers effectively probe microscopic interactions.

Abstract

Microscopic thermodynamic studies can elucidate specific molecular interactions. In this work, we report the microscopic thermodynamics in binary liquid mixtures, which elucidate the role of molecular structure in nonlinear solvent response using femtosecond optical tweezers (FOT). We obtain the excess thermodynamics property of mixing in various Newtonian liquid mixtures by analyzing Microrheology data from FOT. Using our noninvasive 780 nm pulse laser we have trapped micron-sized particles to show how excess viscosity and residual Gibbs free energy change due to mixing. Furthermore, we establish from this study that hydrocarbon chain length and branching can modulate microscopic thermodynamics through intermolecular interaction. This work sheds light on the relationship between thermodynamic properties and viscosity, which is of immense importance for predicting transport properties, mixing, and chemical reactions.